THE NAUTILUS. 39 



The present form is, however, ziot like anything which has been 

 seen by me heretofore. Its warm brown color, smooth, polished 

 surface, lack of any sort of persistent periostracal f ringings, and 

 narrow, though permeable umbilicus, are features serving to set 

 it quite distinctly apart. 



EXPLANATION OF FIGURES. 



Fig. 1, 2. Polygyra sierrana n. sp. Type, from near Weed, 

 Shasta County, California; x 3. 



Fig. 3, 4. Polygyra columbiana shasta n. subsp. Type from 

 La Moine, Shasta County, California; x 2. 



MISCELLANEOUS ROTES ON LAND MOLLUSCA OF THE MADEIRA IS. 



BY T. D. A. COCKERELL. 



Though Porto Santo is the home of so many endemic snails, 

 there still seems to be room for aliens from Europe. Cochli- 

 cella acuta is abundant in certain spots north of Villa Baleira. 

 Helix pisana swarms everywhere. In a spring- in the valley 

 of the Serra do Dentro I found specimens of a small Hydro- 

 biid, which Dr. Pilsbry has kindly identified as Pseudamnicola 

 simttis (Drap.). This species was already known from Ma- 

 deira, but is the first record of a freshwater shell from Porto 

 Santo. 



In 1848 (Proc. Zool. Soc. Lond., p. 110) Pfeiffer described 

 some shells from the Cuming collection, including a species 

 Helix calcarea, collected by Count Vargas in Porto Santo. 

 This shell has since been ignored ; "Wollaston does not mention 

 it. Pfeiffer subsequently listed it as a fossil. In the British 

 Museum I found the type specimen. Mr. Tomlin, to whom I 

 showed it, recognized Pfeiffer's writing on the label under- 

 neath the slab. It is a recent shell, and is a form of Helix 

 piscina, white without bands. The name calcarea cannot be 

 used even in a varietal sense, as there is an earlier H. calcarea 

 Born. 



Also in the British Museum, from the Cuming collection 

 are five specimens of Vitrea miguelina (Pfeiffer), said to be 



* Plate II will appear in next issue. 



